In recent years, thermal transfer systems have been developed to obtain prints from pictures which have been generated electronically from a color video camera. According to one way of obtaining such prints, an electronic picture is first subjected to color separation by color filters. The respective color-separated images are then converted into electrical signals. These signals are then operated on to produce cyan, magenta and yellow electrical signals. These signals are then transmitted to a thermal printer. To obtain the print, a cyan, magenta or yellow dye-donor element is placed face-to-face with a dye-receiving element. The two are then inserted between a thermal printing head and a platen roller. A line-type thermal printing head is used to apply heat from the back of the dye-donor sheet. The thermal printing head has many heating elements and is heated up sequentially in response to the cyan, magenta and yellow signals. The process is then repeated for the other two colors. A color hard copy is thus obtained which corresponds to the original picture viewed on a screen. Further details of this process and an apparatus for carrying it out are contained in U.S. Pat. No. 4,621,271, the disclosure of which is hereby incorporated by reference.
Dye-receiving elements used in thermal dye transfer generally comprise a polymeric dye image-receiving layer coated on a base or support. Transport through the thermal printer and image quality are very dependent on the charging characteristics of the receiver element. During the printing process, static charges can build up in the imaged area as the donor is separated from the receiver after printing each dye patch. If the printer is equipped with a smooth, curved steel chute for sheet guidance, transport problems can be encountered if the charged receiver sheet (image side against the steel chute) conforms too well to the chute during rewind. The attraction of the charged sheet to the steel chute can cause transport of the sheet to cease and failure will occur. This problem is exaggerated when printing is done at elevated humidities such as 85% RH. In addition to transport failures, the charged area on the sheet can attract dust and dirt during the printing process which can cause image quality problems.